Older boat and noticing that the traveler is not moving freely even without any load. Cleaned out the tracks, to no avail. I've searched and found a few possible remedies (replacing the bearings, or simply getting a new traveler car) but also read about a rules change and an ugraded traveler system a few years back. Any suggestions?

Shouldn't be a problem - try to spray some silicone lube on the track and work the car back and forth too - sometimes it just needs a good flushing with fresh water - bearings can be replaced easily as well

The rules change doesn't have anything to do with the ability of the traveler to move in the track. The rule change allows you to relocate the traveler cleat so that its mounted on the rear crossbar rather than on the traveller car. This gives you a fixed point to sheet the traveler from.

First, the travelers work best with at least some vertical load. Second, new bearings are a really good idea as they do wear out (salt, sand, friction...). Third, lube is good too, but not a replacement for a part (or a bunch of parts) that need replacement. You may need the loader to put the new bearings in and then roll the assembled car onto the track. The loader is a blue plastic short piece of artificial track with a hole cut out to load the bearings.